Arsene Wenger had used his programme notes to claim that he now has a 25-man Arsenal squad of unprecedented and identical quality, but this was still a sobering reminder that some of his players are rather more equal than others.
Take Samir Nasri (right). He has been the outstanding player this season, not just for Arsenal but arguably in the entire Premier League, so the sight of him hobbling from the pitch after just 32 minutes while clutching his hamstring was particularly alarming.
Nasri's departure coincided with a loss in momentum for Arsenal yesterday, but far more serious is the news that he is expected to be out for around three weeks and so is almost certain to miss the first leg of the Champions League tie against Barcelona on February 16.
For Wenger, the frustration was compounded by the fact that he had originally intended to rest Nasri ahead of tomorrow's Premier League match against Everton. "It looks a serious hamstring injury," said Wenger. "The plan was to play Tomas Rosicky but he was still too weak because he was sick so I took a gamble on Nasri. It backfired."
Another lost body for at least one match is Sebastien Squillaci who, having returned to play for the first time in more than a month, was again unconvincing and lasted only 42 minutes before being deservedly dismissed for blocking Jack Hunt as he ran clear on goal.
It leaves Arsenal with only two senior centre-backs for the game against Everton but, having again concluded that most Premier League defenders are over-priced, Wenger admitted that he is unlikely to do any business before the transfer window closes tonight.
Despite it being their ninth match in January, Arsenal started fairly brightly yesterday, with Andrey Arshavin and Nicklas Bendtner both creating a flurry of first-half chances.
They took the lead after 22 minutes when Bendtner's shot fortuitously deflected off Peter Clarke and flew past goalkeeper Ian Bennett.
Huddersfield responded admirably and, with Nasri off and Arsenal down to 10 men following Squillaci's red card, they placed their opponents under sustained pressure. The equaliser was thoroughly merited.
Anthony Pilkington's corner was well directed to the edge of the six-yard box and, with Abou Diaby failing to get much height on his jump, Alan Lee headed powerfully past Almunia.
Wenger responded by introducing Cesc Fabregas and Arsenal resumed control. The winner, though, was also controversial with Jamie McCombe getting the wrong side of Bendtner after Fabregas' cute pass. The subsequent contact was minimal but it disrupted Bendtner and persuaded Mark Clattenburg to award a penalty.
Fabregas sent Bennett the wrong way and put Arsenal into the last 16. It also preserved Wenger's record of never having lost an FA Cup tie against a club below the Premier League.
"At 1-1, that record was really under threat but it shows how seriously we take the competition," said Wenger.
(© Daily Telegraph, London)